The CBI president Sir Mike Rake has bowed out of the race to become the next chairman of Barclays, even as the bank attempts to contain the fall-out from a string of new regulatory probes.

Sky News has learnt that Sir Mike told Sir John Sunderland, the non-executive director leading the search, in the last couple of weeks that he no longer wished to be considered as a potential successor to Sir David Walker.

Headhunting sources said that Sir Mike, who also chairs BT Group, had concluded that he would be unable to commit to other roles if he became chairman of Barclays.

His decision makes it likely that Barclays will opt for an external appointment to replace Sir David at a critical point of the turnaround strategy being implemented by Antony Jenkins, the bank's chief executive.

In May, Mr Jenkins outlined plans to cut around 20,000 jobs by the end of 2016 in an attempt to improve the performance of its investment bank and deploy capital where it can generate more productive returns.

Since then, however, his efforts have continued to be hampered by new regulatory investigations.

Last month, the New York attorney-general Eric Schneiderman accused Barclays of misleading investors in its 'dark pool' - a private stock-trading platform - and issued a civil lawsuit against the bank.

Just weeks earlier, Barclays was fined £26m by the City watchdog after one of its traders was found to have sought to manipulate the daily gold price-fix.

The bank also faces months of uncertainty about the outcome of a Serious Fraud Office inquiry into fees paid to Middle Eastern investors during the financial crisis.

The ongoing regulatory woes make the appointment of a credible figurehead as Barclays' chairman especially important.

Sir David joined just under two years ago and vowed to assist with an overhaul of culture and standards at the bank.

He insisted, however, that he would only be prepared to stay for three years, and in February Spencer Stuart, a search firm, was appointed to identify his successor.

One of Britain's most prominent businessmen, Sir Mike has been on the board of Barclays since January 2008, becoming senior independent director in 2011 and then deputy chairman in July 2012.

His decision to withdraw from the search for a new chairman has echoes of the summer of 2012, when Barclays was reeling from the Libor rate-rigging scandal that triggered a £290m fine and the departure of chairman Marcus Agius and chief executive Bob Diamond.

Sir Mike also pulled out of the race then, with Sir David Walker, another City grandee, eventually getting the nod.

The fact that Sir John had assumed oversight of the recruitment process for a new chairman had been interpreted in the City as a signal that Sir Mike was keen on the role; searches for public company chairs are typically overseen by the senior independent director.

Institutional shareholders in Barclays are understood to have expressed mixed views about Sir Mike's candidacy.

Some are understood to have been unhappy at the prospect of him replacing Sir David because of his vocal support in the past for Mr Diamond's leadership of the bank.

His six-and-a-half years on the Barclays board had also led a number of investors to demand a fresh pair of eyes to replace Sir David, particularly in the wake of a new row over pay at this year's annual meeting.

Just over one-third of shareholders decided not to support Barclays' remuneration report, reflecting anger at the payment of a £2.4bn bonus pool despite a slump in annual profits.

Sir Mike's withdrawal from the search for a new chairman leaves Tim Breedon, the former boss of Legal & General, as one of the few potential non-executives who could step up to replace Sir David.

It is unclear which external candidates are under consideration for the chairmanship.

Barclays declined to comment on Saturday, while Sir Mike could not be reached.